Improvement in screw-drivers



'mina @eine geen omit.

Lette/rs Patent No. 99,781, dated February 15, 1870.`

IMPROVEMENT IN SCREW-DRIVERS.

The Schedule referred to in these Letters Patent and making part oi the same To all whom it may concern Be it known that I, WILLIAM H. MART'XN, of Boston, in the county of Suffolk, and State of Massaclnv,

setts, have invented certain new and useful Improv-ements'in Screw-Drivers; and I do hereby declare that J the iollowlni,r is a full and exact description thereof,

reference being had to the accompanyingrdrawings, and

to the4 lett-ers of reference marked thereon.

The nature of my invention consists in combining with the iron of an ordinary screw-driver, a cylinder containing a cone-shaped socket. Said cyl'iinler'slides upm the iron of the screw-driver, and is kept; doivn over the point of the screw-driver by a sprinar so'as to enclose' the head ofthe screw, and thus form a guard to prevent the point of the screw-driver from slippingr from the niek in the head of the screw, as Well as t-o prevent the head of the screw frein Splitting. The socket heilig conical itwill iit various sized screws'.

To enable others skilled in the art to make and use my invention, I will proceell to -ilescrihe its construction and use.

Drawings. Figure l is aperspective view showing' my invention coni plete.

Figure 2 is a longitndinal section of my invention. A is an ordinary screw-driver, and may be tted to a bit-stock, or be'nrovided with an ordinary handle.

B is a metallic cylinder fitting on to the end of the screwdriver, .as shown.

The lower end has a conical socket, 1), and is also slotted, as shown at 3, to admit the pointof thev screwdriver to slide freely.

S is a spring attached to A, and so arranged as to 'exert a pressure, against the shoulders H H of the Y socket-piece B, thuslloliling the end l) of the socketpiece beyond the. point C of the screw-driver.

'.lhe socket l) is made conical, so that it may iit` the head ot' different sized screws.

The use of my invention is too obvious to require ilescription.

lts advantages are that it serves as a kind of guide t'or upplying'the driver to the screw; it serves to prevent the driver from slipping from the nick of the screw., and also to prevent the head of' the screw from splitting.

What Iclailn my invent-ion, vand desire to secure h v Letters Patent ofthe United States, is

The combination of' fthe screw-driver A G Wit-l1 the tube or socket B, whenall the parts are constructed to operate as shown and described and for the purpose set forth. f

WM; ll. MARTYN.

Witnesses:`

FRANK G. PARKER, A. HUN'. BERRY. 

